It is common practice to provide protection for walls and window areas in the corridors and other high traffic public and service spaces, such as kitchens, laundries, file and mail rooms, and cafeterias, of commercial manufacturing and health care facilities against impact from carts and equipment, and a variety of bumper rails, crash or trolley rails and hand rails specifically designed to provide protection is available and in widespread use. The assignee of the present invention has for some time marketed a line of wall protection products under its trademark ACROVYN, such products including hand rails and wall bumper guards constructed in accordance with U.S. Pat. Nos. 3,717,968 and 3,825,229 which consist of longitudinally continuous metal structural members and bumper members coextensive with the structural members and made of a resilient impact-resistant polymeric material (plastic), such as a mixture of vinyl and acrylic polymers. The plastic impact members have provided outstanding performance in resisting marring and breakage and in protecting the wall surfaces on which they are mounted, and the fact that they can be made in a variety of colors makes them very popular with architects and designers for aesthetic reasons as well as for their ability to retain their original, like-new appearance for many years with a minimum of maintenance.
The hand rails and bumper guards are generally entirely effective when there is reasonable assurance that impacts will occur at a relatively limited vertical zone at the height at which the hand rails and bumper guards are installed. On the other hand, there are occasions when the nature of the equipment rolled or carried through corridors or other areas where wall protection is provided may impact at various heights over a wider range than the two to four inches for which bumper guards and hand rails provide protection. Moreover, cost considerations may lead the building owner to choose a simpler wall protection device, such as a so-called crash rail or trolley rail.
One form of commercially available crash or trolley rail consists of a series of relatively narrow metal clips rigidly fastened to the wall and a generally U-shaped plastic impact member snapped onto the clips. The front face of the crash member is substantially flat and has a height of several inches, typically eight inches, thus providing protection against impacts over a fairly wide range of heights. The mounting flanges by which the impact member is attached to the clips provide a stand-off distance of about one inch, and spacers can be provided to increase the stand-off distance, if desired. The space between the front face of the crash member and the wall is entirely open which means that the front face is subject to deformation upon impact, and that deformation may be sufficiently large to dislodge one of the retainer flanges from the clips, thus resulting in partial or full dislodgement of the crash rail from the mounting clips.